1. Field of the Invention
The present invention relates generally to magnetic disk drives with load/unload ramps and, more particularly, to the load/unload tab on the distal end of the actuator
2. Description of the Background Art
A magnetic disk drive storage device typically comprises one or more thin film magnetic disks, each having at least one data recording surface including a plurality of concentric tracks of magnetically stored data, a spindle motor and spindle motor controller for supporting and rotating the disk(s) at a selected RPM, at least one read/write transducer or xe2x80x9cheadxe2x80x9d per recording surface formed on a slider for reading information from and writing information to the recording surface, a data channel for processing the data read/written, a positionable actuator assembly for supporting the transducer in close proximity to a desired data track, and a servo system for controlling movement of the actuator assembly to position the transducer(s) over the desired track(s).
Each slider is attached on one surface to an actuator arm via a flexible suspension and includes on an opposite side an air bearing surface (ABS) with an aerodynamic pattern of protrusions on the air bearing surface which enable the slider to fly at a constant height close to the disk during operation of the disk drive. The aerodynamic pattern generally includes a pair of rails, one on each side of the slider. In contact start/stop disk drive designs, the slider and transducer are only in contact with the recording surface when the spindle motor is powered down. As the disk begins to rotate, an air flow is generated which enters the slider""s leading edge and flows in the direction of its trailing edge. The air flow generates a positive pressure on the ABS, lifting the slider above the recording surface. As the spindle motor reaches operating RPM, the slider is maintained at a nominal fly height over the recording surface by a cushion of air. Then at spin-down, fly height drops until the slider is once again in contact with the disk.
Because contact start/stop recording subjects the slider and transducer to extensive wear, recent disk drive designs alternatively employ load/unload technology. According to this design, a ramp is provided for each slider/suspension assembly at the inner or outer diameter of the disk where the slider is parked securely while the spindle motor is powered down. During normal operation, the disk speed is allowed to reach a selected RPM (which may be below the normal operating RPM) before the head is loaded onto the disk from the ramp on the air cushion generated by the disk""s rotation. In this manner, the slider flies over the disk without significant contact with the disk surface, eliminating contact start/stop wear.
U.S. Pat. No. 5,572,387 discloses a head suspension assembly for use with a magnetic disk drive having a load/unload ramp. FIG. 2D shows an actuator with load tang 18 centered at the distal end of the actuator. The load/unload ramp is generally positioned so that the edge of the ramp overlies a portion of the outer diameter of the disk. During unloading, the actuator is moved radially to the outer diameter of the disk where tang contacts the ramp to move the actuator away from the disk.
Integral Corporation sold a disk drive where the load/unload tang was offset to the outer diameter side of the actuator arm so that the edge of the ramp could be positioned at the edge of the disk thereby enabling the use of the entire disk for storage. Also, this design avoided the problem of particles falling from the ramp surface onto the disk.
Unfortunately, it has been discovered that during load and unload, the slider will, on occasion, inadvertently contact the disk with one or both of the rails causing loss of data. The problem is significant enough so that most users now avoid using for storage the outer diameter of the disk near the edge of the ramp.
Therefore, there is still a need in the art for a load/unload scheme that enables the use of more of the disk area for storage.
It is the object of the present invention to provide a load/unload scheme that enables the use of more of the disk area for storage.
Other objects and advantages will be apparent from the following disclosure.
The present invention relates to a magnetic disk drive for reading or writing magnetically, comprising: (i) a base; (ii) one or more magnetic disks; (iii) a hub fixedly attached to the disks for supporting the disks; (iv) a motor operable to rotate the hub; (v) one or more magnetic read/write heads supported on one or more sliders, each associated with the surface of a disk; (vi) one or more actuator assemblies for supporting the sliders and moving the sliders radially across the disks from the hub to the outside diameter of the disk, each actuator assembly having a top side and an opposite bottom side which faces the disk and an inner diameter side which faces the hub and an opposite outer diameter side; each actuator assembly having a tab positioned at its distal end and adjacent to the inner diameter side of the actuator assembly; and (vii) a load/unload structure attached to the base and positioned near the outer diameter of the disk for displacing the one or more heads from the disk, the load/unload structure comprising a one or more ramps for receiving the tabs of the actuator assemblies.
A more thorough disclosure of the present invention is presented in the detailed description of the invention, which follows, and the accompanying figures.